Association of C-reactive protein levels with fasting and postload glucose levels according to glucose tolerance status

Abstract

Background and aims: Several studies show that high serum C-reactive protein (CRP) levels are associated with an increased risk of diabetes, data that strongly supports a possible role for inflammation in diabetogenesis. The aim of this study was to determine whether elevated CRP levels are associated with fasting plasma glucose (FPG) and/or postload glucose levels according to the glucose tolerance status.

Methods: A total of 169 healthy males and non-pregnant females aged 18-65 years were enrolled in a population-based cross-sectional study. Individuals were allocated into groups with a new diagnosis of normal glucose tolerance (NGT) (n = 82), impaired fasting glucose (IFG) (n = 54), and impaired glucose tolerance (IGT) (n = 33). Elevated CRP was defined by CRP levels >3.0 and <10.0 mg/L, IFG by FPG ≥100 and <126 mg/dL, and IGT by plasma glucose concentration 2 h postload ≥140 and <200 mg/dL. A multiple regression linear analysis adjusted by body mass index, waist circumference, and lipid profile was performed to evaluate the association between CRP levels (independent variable) with FPG and 2 h postload glucose levels (dependent variables).

Results: Multivariate linear regression analysis showed a significant association between hsCRP levels with FPG (β = 0.536; 95% CI 1.03-5.1, p = 0.005) and 2 h postload glucose (β = 0.209; 95% CI 1.31-2.97, p = 0.01) in the IGT group, but not with FPG (β = 0.147; 95% CI 0.55-2.0, p = 0.25) and 2 h postload glucose (β = 0.151; 95% CI 0.83-3.2, p = 0.24) in the IFG group.

Conclusions: Elevated CRP levels are associated with FPG and 2 h postload glucose in the individuals with IGT, but not in subjects with IFG or NGT.

Keywords: C-reactive protein; Fasting plasma glucose; Glucose tolerance status; Postload glucose.